Complete deterministic stream X-machine testing

One of the strengths of using stream X-machines to specify a system is that, under certain well defined conditions, it is possible to produce a test set that is guaranteed to determine the correctness of an implementation. However, the existing method assumes that the implementation of each processing function is proved to be correct before the actual testing can take place, so it only test the system integration. This paper presents a new method for generating test sets from a deterministic stream X-machine specification that generalises the existing integration testing method. This method no longer requires the implementations of the processing functions to be proved correct prior to the actual testing. Instead, the testing of the processing functions is performed along with the integration testing.Accepted in revised form 27 February 2004 by D.A. Duce     

Testing Conformance to a Quasi-Non-Deterministic Stream X-Machine

Stream X-machines have been used in order to specify a range of systems. One of the strengths of this approach is that, under certain well-defined conditions, it is possible to produce a finite test that is guaranteed to determine the correctness of the implementation under test (IUT). Initially only deterministic stream X-machines were considered in the literature. This is largely because the standard test algorithm relies on the stream X-machine being deterministic. More recently the problem of testing to determine whether the IUT is equivalent to a non-deterministic stream X-machine specification has been tackled. Since non-determinism can be important for specifications, this is an extremely useful extension. In many cases, however, we wish to test for a weaker notion of correctness called conformance. This paper considers a particular form of non-determinism, within stream X-machines, that will be called quasi-non-determinism. It then investigates the generation of tests that are guaranteed to determine whether the IUT conforms to a quasi-non-deterministic stream X-machine specification. The test generation algorithm given is a generalisation of that used for testing from a deterministic stream X-machine. Received November 1999 / Accepted in revised form December 2000     

Testing Conditions for Communicating Stream X-machine Systems

X-machines were proposed by Holcombe as a possible specification language and since then a number of further investigations have demonstrated that the model is intuitive and easy to use. In particular, stream X-machines (SXM), a particular class of X-machines, have been found to be extremely useful in practice. Furthermore, a method of testing systems specified as SXMs exists and is proved to detect all faults of the implementation provided that the system meets certain “design for test conditions”. Recently, a system of communicating SXMs was introduced as a means of modelling parallel processing. This paper proves that each communicating machine component can be transformed in a straightforward manner so that the entire system will behave like a single stream X-machine - the equivalent SXM of the system. The paper goes on to investigate the applicability of the SXM testing method to a system of communicating SXMs and identifies a class of communicating SXMs for which the equivalent SXM of the system meets the “design for test conditions”. Received November 1999 / Accepted in revised form June 2001     

Simulation testing of automata

Although many transducer testing techniques can establish whether a system Imp correctly implements a specification Spec, the notion of 'correctness' used in this context is often rather weak, in that it fails to distinguish correctly between behaviours that are related functionally, but distinct as processes. By appealing to the process-theoretic notion of (strong) simulation, we develop a theory of transducer, process and FSM testing capable of establishing whether Imp is a full simulation of Spec. We show, moreover, that our approach is consistent with top–down integration-testing approaches. Received June 2004 Revised February 2005 Accepted March 2005 by M. Harmann and R. M. Herons     

The design and implementation of a Jini/Java-based A/V stream control and management

Distributed multimedia applications make diverse demands on communication services and quality of service. These requirements must be met end-to-end in an efficient and integrated manner through the enabling middleware of end systems and communication networks. The middleware should allow an adaptive quality of service (QoS) to be specified and supported; it should also provide application programming interfaces with integrated group communication support that simplify the programming task of multimedia applications. This paper focuses on the latter aspect and presents a distributed solution known as Stream Manager. Stream Manager allows heterogeneous media devices to be connected by the same session initiation procedures of Stream Manager. Through an underlying network connection management service, it allows a new group stream to be supported in addition to the OMGs unicast streams and point-to-multipoint multicast streams. The basic operations of Stream Manager and its application interfaces will be described, and the design and implementation of a prototype in Jini/Java will be presented. The performance of the prototype was measured experimentally in terms of throughput, delay, and latencies of joining and leaving a stream. We then compared its performance with that of streams handled by using Java RMI, Java sockets, and CORBA A/V stream. The performance of our system was found to be superior to that of Java RMI and comparable to that of Java socket but slightly inferior to that of CORBA A/V stream due to the higher intrinsic Java processing overhead.     

探析白盒测试之基于路径测试

软件测试的目标是发现尽可能多的错误,提高软件质量和可靠性,对于规模相对较小,结构相对简单的软件,采用基于路径测试的白盒测试不失为一种很好的测试方法。     

Comparison of stream merging algorithms for media-on-demand

Stream merging is a technique for efficiently delivering popular media-on-demand using multicast and client buffers. Recently, several algorithms for stream merging have been proposed, and in this paper we perform a comprehensive comparison of these algorithms. We present the differences in philosophy and mechanics among the various algorithms and illustrate the tradeoffs between their system complexity and performance. We measure performance in total, maximum, and time-varying server bandwidth usage under different assumptions for the client request patterns. We also consider the effects on clients when the server has limited bandwidth. The result of this study is a deeper understanding of the system complexity and performance tradeoffs for the various algorithms.Amotz Bar-Noy: This work was done in part while the author was a member of the AT&T Labs-Research, Shannon Lab, Florham Park, NJ.Justin Goshi: Corresponding author. This work was done in part at AT&T Labs-Research, Shannon Lab, Florham Park, NJ.Richard E. Ladner: This work was done in part at AT&T Labs-Research, Shannon Lab, Florham Park, NJ and partially supported by NSF grants No. CCR-9732828 and CCR-0098012.A preliminary version of this paper appeared in Multimedia Computing and Networking 2002.     

软件测试方法简述与展望

软件测试是一门重要的、具有广泛应用的学科,随着应用系统的不同,软件的测试方法呈现多样性。该文从概念、基本问题、方法、任务等各个方面进行评述,讨论了待解决的问题,并对今后的发展方向进行了展望。     

Analysing a stream authentication protocol using model checking

In this paper, we consider how one can analyse a stream authentication protocol using model checking techniques. In particular, we will be focusing on the Timed Efficient Stream Loss-tolerant Authentication Protocol, TESLA. This protocol differs from the standard class of authentication protocols previously analysed using model checking techniques in the following interesting way: an unbounded stream of messages is broadcast by a sender, making use of an unbounded stream of keys; the authentication of the n-th message in the stream is achieved on receipt of the n+1-th message. We show that, despite the infinite nature of the protocol, it is possible to build a finite model that correctly captures its behaviour.     

Generating Test Sets from Non-Deterministic Stream X-Machines

X-machines were proposed by Holcombe as a possible specification language and since then a number of further investigations have demonstrated that the model is intuitive and easy to use as well as general enough to cater for a wide range of applications. In particular (generalised) stream X-machines have been found to be extremely useful as a specification method and most of the theory developed so far has concentrated on this particular class of X-machines. Furthermore, a method for testing systems specified by stream X-machines exists and is proved to detect all faults of the implementation provided that the system meets certain initial requirements. However, this method can only be used to generate test sequences from deterministic X-machine specifications. In this paper we present the theoretical basis for a method for generating test sets from non-deterministic generalised stream X-machines. Received November 1999 / Accepted in revised form September 2000     

Stretch-minimising stream surfaces

We study the problem of finding stretch-minimising stream surfaces in a divergence-free vector field. These surfaces are generated by motions of seed curves that propagate through the field in a stretch minimising manner, i.e., they move without stretching or shrinking, preserving the length of their arbitrary arc. In general fields, such curves may not exist. However, the divergence-free constraint gives rise to these ‘stretch-free’ curves that are locally arc-length preserving when infinitesimally propagated. Several families of stretch-free curves are identified and used as initial guesses for stream surface generation. These surfaces are subsequently globally optimised to obtain the best stretch-minimising stream surfaces in a given divergence-free vector field.Our algorithm was tested on benchmark datasets, proving its applicability to incompressible fluid flow simulations, where our stretch-minimising stream surfaces realistically reflect the flow of a flexible univariate object.     

软件自动化测试方案的效益分析

首先对手工测试与自动化测试进行比较,然后提出自动化测试方案选择需要考虑的方面,并结合工作实践,给出了一种自动化测试投资回报率的计算方法,论述了自动化测试带来的效益,并指出自动化测试的引入应当选择合适的时机,实现手工测试和自动化测试实现完美结合。     

自动化回归测试的技术和实现

提出了两种提高回归测试自动化程度的技术。其中一种技术采用数据驱动的方式,使得测试脚本成为可以驱动所有类似测试用例组的通用脚本,同时,实现了测试执行和测试逻辑的分离,使得测试用例的修改和维护更加容易。介绍的另一种技术使用附加的动态链接库来恢复被测软件的图形界面状态,使得软件图形界面的自动测试不易受到被测软件状态改变的影响,提高了整个自动测试系统的健壮性。     

The design and implementation of a grammar-based data generator

DGL is a context-free grammar-based language for generating test data. Although many of the features of DGL are implemented in a straighforward way, the implementation of several of the most important features is neither trivial nor obvious. Before one can understand the implementation of these features, however, it is necessary to understand the overall structure of the compiler and its output, which was designed to be flexible enough to incorporate new features easily. Variables and chains are two of the most important features of DGL, and also two of the trickiest features to implement. The run-time dictionaires, which are built into the C code generated by the compiler, are implemented as pure code rather than as table-look-up routines. The compiler itself is reasonably straightforward, except for the expansion of character sets and compile-time macros. These two features can cause the ‘multi-dimensional’ expansion of a string, the implementation of which must be carefully designed.     

Java多线程测试策略及测试方法探讨

Based on analyzing the features of Java multithread, testing strategies and methods are discussed in this paper. Java multithread testing is consist of class testing,integration block testing and system testing. The main testing methods for Java multithread are proposed, such as inherit testing, synchronization testing and synchronization efficiency testing.     

数字集成电路测试技术应用

介绍了数字集成电路测试系统的基本构成,当今超大规模数字集成电路测试的基本原理,并在掌握这些测试理论的基础之上针对不同类型的测试系统利用其各自测试语言进行编程的测试技术应用,同时也提出了集成电路测试技术面临的挑战和未来发展趋势。     

湖南农业信息化综合服务平台测试方法分析

湖南农业信息化综合服务平台是综合运用信息技术、通讯技术与电子商务技术,面向湖南广大农村地区进行信息化推广与宣传的平台。当前系统开发已进入重要的测试阶段,本文从硬件和软件两个角度,分别阐述服务平台进行测试的策略与方法,特别论述自动化测试工具Loadrunner在软件测试中的重要作用,并对测试结果进行了相应分析。     

E-parser: An implementation of a deterministic GB-related parsing system

This paper describes an implementation of a deterministic parsing system, described in Nordgård (1993). The syntax of heuristic rules and how the rules interact with the basic operations of the parser constitute the bulk of the article. The implementation is written in Medley Interlisp, and the system can be run on Sun or Xerox workstations. Torbjørn Nordgård is associate professor of computational linguistics in the Department of Linguistics and Phonetics, University of Bergen. His research interests include computational linguistics, theoretical linguistics, in particular formal syntax and semantics, and philosophy of science. He has published A GB-Related Parser for Norwegian(Bern: Peter Lang) and he is one of the authors of Generativ syntaks: Ei innføring via norsk(Oslo: Novus).     

Study of a simulated stream machine for dataflow computation

In this paper, a stream-based dataflow architecture is proposed, and its simulation model, which has helped to evaluate the effectiveness of the proposed architectural concept, is discussed. The machine integrates the conventional Von Neumann type of control flow subsystem with a dataflow processing element of token storage type. The control flow unit tackles the dynamic nature of the stream structure including input/output whereas the dataflow unit does the computation part in an applicative style. A pipelined version of the stream machine is also discussed. The effectiveness of the machine is studied by running a few example programs in the simulated machine. The machine is expected to be useful in real time signal processing applications.     

Multivariable stream data classification using motifs and their temporal relations

Multivariable stream data is becoming increasingly common as diverse types of sensor devices and networks are deployed. Building accurate classification models for such data has attracted a lot of attention from the research community. Most of the previous works, however, relied on features extracted from individual streams, and did not take into account the dependency relations among the features within and across the streams. In this work, we propose new classification models that exploit temporal relations among features. We showed that consideration of such dependencies does significantly improve the classification accuracy. Another benefit of employing temporal relations is the improved interpretability of the resulting classification models, as the set of temporal relations can be easily translated to a rule using a sequence of inter-dependent events characterizing the class. We evaluated the proposed scheme using different classification models including the Naive Bayesian, TFIDF, and vector distance models. We showed that the proposed model can be a useful addition to the set of existing stream classification algorithms.